Hydroformylation and Isomerization of Allene and Propyne: A Density Functional Theory Study

The [HCo(CO)3]-catalyzed hydroformylation of allene and propyne has been investigated at the B3LYP level of density functional theory. It is found that hydroformylation of allene favors the linear anti-Markovnikov product in high regioselectivity both kinetically and thermodynamically. The origin of this regioselectivity comes from the enhanced stability of the eta3-allylic intermediate [(eta3-CH2CHCH2)Co(CO)3]. By contrast, propyne does not show any regioselectivity. The possible interconversion between allene and propyne mediated by [HCo(CO)3] has been explored.